Connector device for pipes

ABSTRACT

A connecting device for a plug-in connection of at least one pipeline having a housing part having at least one receiving opening for the insertion of the pipeline. A clamping ring is arranged in the receiving opening and, in order to lock the pipeline in place, interacts with an inner one of the housing part. The housing part is made in two parts including a base part and an insert part, which is connected to the base part via a snap-in action forming-fitting connection. The insert part has a direct seal for resting on the circumference of the inserted pipeline. The insert part is formed of a first relatively hard and dimensionally stable plastic material, and has a dirt seal consists of a second, relatively soft and elastic plastic material and is molded directly into the first material as a single piece with a cohesive material joint therebetween.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims Priority to DE 202 14 847.5, filed Sep. 24,2002, and PCT/EP03/10555, filed Sep. 23, 2003.

FIELD OF THE INVENTION

The present invention relates to a connecting device for the plug-inconnection of at least one pipeline (pipeline or hose line for gases orliquids). The device includes a housing part having at least onereceiving opening for the insertion of the pipeline, and a slotted and,as a result, radially elastically deformable clamping ring, which isarranged in the receiving opening and, in order to lock the pipeline inplace, interacts via an outer cone with an inner cone of the housingpart. The housing part be is made in two parts from a base part and aninsert part, which is connected to the latter via a snap-actionform-fitting connection and has the inner cone, and the insert parthaving a dirt seal for resting on the circumference of the insertedpipeline.

BACKGROUND OF THE INVENTION

A connecting device of the general type of this application is disclosedin EP 0 733 844 B1. In this case, the insert part consists of asingle-piece plastic molded part, a dirt seal, which is intended toprevent dust, dirt, moisture (spray water) and the like frompenetrating, being molded onto it as a single piece as an encirclingsealing lip. Before the pipeline is inserted, this sealing lip extendsobliquely radially inward in the insertion direction in such a mannerthat it is somewhat elastically widened by the inserted pipeline andthen rests against it in a sealing manner. For the purpose of being ableto release the pipeline, the insert part here has two elastic latchingarms which engage with latching attachments into the base part and intolatching openings formed there. Each latching arm has an actuatingsection which protrudes outward from the base part. This knownconnecting device has essentially been well tried and tested, but, inparticular, the dirt seal is still not optimal. In addition, theprotruding actuating attachments of the latching arms may be obstructiveor may even result in an unintentional release.

The present invention is based on the object of further improving aconnecting device of the described generic type in respect of its useproperties using economical means.

SUMMARY OF THE INVENTION

According to the invention, the above objects are achieved by the insertpart consisting of a first, relatively hard and dimensionally stableplastic material and by the dirt seal, consisting of a second,relatively soft and elastic plastic material, being molded directly ontoit as a single piece with a cohesive material joint. This advantageousconfiguration makes it possible for the dirt seal to be designedspecifically in terms of shape and/or material to provide an optimumsealing function. For example, use can be made of a soft and elasticmaterial which is optimally suitable for the seal, and it is alsopossible for favorable shapes, in particular bead-like annular crosssections to be realized, as a result of which a good sealing action isobtained when resting on the circumference of the pipeline. In addition,this configuration also permits an easy pushing-in and, if appropriate,pulling-out of the pipeline because, in contrast to lip seals, in thecase of bead seals relative pushing movements cannot result in damagingdeformations of the seal. The insert part itself can be designed foroptimum mechanical properties through the selection of a suitablematerial, this being of significance in particular for the supporting ofthe clamping ring. However, the insert part according to the inventioncan nevertheless be produced cost effectively in a two-componentinjection molding process.

For a good sealing against dirt, it is furthermore advantageous if theinsert part is of sleeve-shaped design and is inserted or can beinserted into a widened portion of the receiving opening of the basepart, in particular with a press fit, and hence in a manner such that itprovides a seal at least against the penetration of dirt and similarforeign bodies. In this case, the insert part, in the inserted state,preferably lies completely within the base part and ends flush on theopening side. By means of this advantageous configuration, an optimumsealing against the penetration of dirt, moisture and similar foreignbodies is achieved, even in the connecting or contact region between theinserted insert part and the base part completely accommodating thelatter. The completely recessed arrangement of the insert part withinthe base part results in a very compact constructional form withoutprotruding parts which could otherwise result in practical use incollisions with other parts in the region surrounding the connectingdevice or even—in the case of a releasable configuration of the insertpart—to an unintentional release of the pipeline.

Further advantageous refinement features of the invention are containedin the subclaims and in the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below with reference to aplurality of preferred exemplary embodiments which are illustrated inthe drawing, in which:

FIG. 1 shows a partially cut-open perspective view of a first embodimentof a connecting device according to the invention,

FIG. 2 shows a partially cutaway side view of the embodiment accordingto FIG. 1,

FIG. 3 shows a section in the plane III-III according to FIG. 2,

FIG. 4 shows a section in the plane IV-IV according to FIG. 3,

FIG. 5 shows an enlarged end view just of the separate insert part inthe arrow direction V according to FIG. 3,

FIG. 6 shows a section in the plane VI-VI according to FIG. 5,

FIG. 7 shows a section in the plane VII-VII according to FIG. 5,

FIG. 8 shows a partially cutaway perspective view of a furtherembodiment of the connecting device according to the invention,

FIG. 9 shows a half cutaway side view of the embodiment according toFIG. 8,

FIG. 10 shows an axial section in the plane X-X according to f FIG. 9,

FIG. 11 shows a perspective view of a further embodiment of theconnecting device,

FIG. 12 shows an enlarged longitudinal section of the embodimentaccording to FIG. 11,

FIG. 13 shows a perspective view of a further embodiment of theconnecting device,

FIG. 14 shows a longitudinal section of the embodiment according to FIG.13,

FIG. 15 shows a perspective view of a further embodiment of theconnecting device,

FIG. 16 shows an enlarged longitudinal section of the embodimentaccording to FIG. 15,

FIG. 17 shows a further exemplary embodiment of a connecting deviceagain in perspective view,

FIG. 18 shows an enlarged longitudinal section of the embodimentaccording to FIG. 17,

FIG. 19 shows a perspective view just of the separate insert parttogether with advantageous refinement features,

FIG. 20 shows a side view of the insert part in the arrow direction XXaccording to FIG. 19,

FIG. 21 shows a section in the plane A-A according to FIG. 20,

FIG. 22 shows a section in the plane B-B according to FIG. 21,

FIG. 23 shows a section in the plane F-F according to FIG. 20,

FIG. 24 shows a cross section in the plane C-C according to FIG. 20,

FIG. 25 shows a cross section in the plane E-E according to FIG. 22,

FIG. 26 shows a cross section in the plane D-D according to FIG. 20, and

FIG. 27 shows, in an expedient refinement, an enlarged detail in theregion A according to FIG. 21.

DETAILED DESCRIPTION OF THE INVENTION

In the various figures of the drawing, identical parts are alwaysprovided with the same reference numbers, so that every description of apart which may appear only once with reference to a certain figure ofthe drawing also applies analogously to the other figures of the drawingin which the part with the corresponding reference number can likewisebe seen.

In all of the exemplary embodiments, a connecting device 1 according tothe invention comprises a housing part 2 with a receiving opening 4,which is open on one side, for the axial insertion of an end of apipeline 6, and of a clamping ring 8, which is arranged in the housingpart 2 or in the receiving opening 4 and is intended for locking thepipeline 6, which is inserted axially, i.e. in the direction of aplug-in axis 10, in place. In this case, the connecting device 1 permitsa simple and rapid installation of the pipeline 6, which consists inparticular of plastic, by simple insertion into the housing part 2without other installation steps. The clamping ring 8 sits in a widenedportion of the receiving opening 4 in such a manner that it surroundsthe receiving opening 4 and therefore the inserted pipeline 6. At onepoint of its circumference, the clamping ring 8 has a slot which passesaxially and radially through it, i.e. an interruption in itscircumferential profile, as a result of which it can be radiallyelastically widened and/or constricted. In its inner circumferentialregion, the clamping ring 8 has—see in this respect in particular thelarger illustrations in FIGS. 12, 14, 16 and 18—(at least) one radiallyinwardly protruding, encircling tooth edge 12. The clamping ring 8furthermore has an outer cone 14 which, in order to lock the pipeline 6in place, interacts with an inner cone 16 of the housing part 2 in sucha manner that, when there is a pull on the pipeline 6 in the releasedirection (arrow direction 18 in FIG. 2), i.e. when there is a movementcounter to the insertion direction (arrow 20 in FIG. 1), the clampingring 8 is initially carried along by means of the frictional bearing ofits tooth edge 12 until an outer cone 14 comes to rest in the inner cone16 of the housing part 2. If the pulling continues, a radially inwardlydirected force is produced via the cones 14, 16, by means of which forcethe clamping ring 8 is elastically constricted, so that the tooth edge12 interacts with the essentially smooth-faced, cylindrical outercircumference of the pipe in a frictional and/or form-fitting manner andthe pipe is thus locked in place to prevent it from being pulled out.

For the pressure-tight sealing of the pipeline 6, a sealing ring 24(pressure seal) is arranged within the housing part 2 in the regionbetween the clamping ring 8 and a hole step 22. In addition, asupporting sleeve 26 which is coaxial with the plug-in axis 10 ispreferably arranged within the housing part for the frictionalengagement in the inserted pipeline 6. The supporting sleeve 26therefore supports, from the inside, the pipeline 6 placed on to it, onthe one hand, against the radial force applied via the clamping ring 8and, on the other hand, also against the bearing force of the sealingring 24. As a result, the connecting device 1 according to the inventionis, in principle, also suitable for hose lines.

For the purpose of being able to produce and fit the connecting device1, the housing part 2 is made in two parts from a base part 28 and aninsert part 32, which is connected to the latter via a snap-actionform-fitting connection 30 (form-fitting latching connection with anactive-surface undercut angle of greater/less than 90°) and has theinner cone 16. The insert part 32 has a dirt seal 34 for resting on thecircumference of the inserted pipeline 6.

According to the invention, the insert part 32 having the dirt seal 34is formed as a single-piece two-component molded part from two differentplastic materials, to be precise, the insert part 32 consists of afirst, relatively hard and dimensionally stable plastic material whilethe dirt seal 34, consisting of a second, relatively soft and elasticplastic material, is molded directly onto it as a single piece with acohesive material joint. The plastic material is preferably athermoplastic elastomer (TPE). In this case, the dirt seal 34, see inthis respect in particular FIG. 6, has, on its radially inwardlypointing side, a bead-like sealing region for resting on thecircumference of the pipeline 6.

The insert part 32 together with the dirt seal 34 is overall ofessentially sleeve-shaped design and is inserted or can be inserted intoa widened portion 36 of the receiving opening 4 of the base part 28,preferably with a press fit, and hence in a manner such that it providesa seal at least against the penetration of dirt and similar foreignbodies. In this case, it is particularly advantageous if the insert part32, in the inserted state, lies completely within the base part 28 andends flush on the opening side. The result is an advantageously compactconstructional form of the connecting device 1 which, on the openingside, has a planar end surface which is closed toward the pipeline 6 viathe dirt seal 34.

The snap-action form-fitting connection 30 may be a closed latchingelement design (not illustrated) encircling in the circumferentialdirection, which, because of the form-fitting connection achieved(undercut ≧90°), results in the pipeline not being able to be released.

However, for the purpose of being able to release the pipeline 6,provision is made in the preferred embodiments illustrated for thesleeve-shaped insert part 32—see in this respect in particular theseparate, enlarged illustrations in FIGS. 5 to 7 and FIGS. 19 to 27—tohave at least two radially elastic, diametrically opposite spring arms40 which are formed by longitudinal slots 38. Each spring arm 40 engagesreleasably, by means of a radially outwardly protruding, lug-likelatching attachment 42, in a form-fitting manner, i.e. with an undercutof ≧90°, into a corresponding latching opening 44 of the base part 28.In this case, the latching openings 44 are designed as radial passageopenings, so that the latching attachments 42 can be reached fromoutside with a suitable tool for release purposes and can be movedradially inward, as a result of which the pipeline 6 can be removedtogether with the clamping ring 8 and the insert part 32 (arrowdirection 18 in FIG. 2).

In the preferred refinement described, it is furthermore advantageous ifthe longitudinal slots 38 of the insert part 32 are completely filledwith the material of the dirt seal 34 (see in this respect the sectionin the region of the longitudinal slots 38 in FIGS. 7 and 23). Thisrefinement results in ensuring an optimum sealing against dirt becauseactual gaps are avoided even in the region of the longitudinal slots 38.Nevertheless, the elasticity of the sealing material filling thelongitudinal slots 38 (in particular a TPE) permits the required radialmovement of the spring arms 40.

The above-described supporting sleeve 26 is expediently formed as asingle piece with the base part 28.

In principle, the connecting device 1 may be a direct part of anydesired assembly part (for example a valve block). However, in theembodiments illustrated, the housing part 2 can be connected to anydesired further assembly part (not illustrated) via (at least) oneconnecting section 46. Various embodiments for this will be describedbelow.

Thus, in the case of the embodiment according to FIGS. 1 to 4, theconnecting section 46 is designed as a pipe attachment 48 for insertioninto a receiving opening. This may also be a receiving opening 4 of afurther connecting device 1 according to the invention. In theembodiment illustrated, the pipe attachment 48 is arranged, in respectof its longitudinal axis, at right angles to the plug-in axis 10, sothat it is an angle connector. In this case, in a preferred refinement,provision is made for the base part 28 to be formed as a single piecewith the pipe attachment 48 as a two-component molded part of plastic,the region of the pipe attachment 48 consisting of a relatively softmaterial, to be precise, in particular corresponding to the material ofcustomary plastic pipelines 6, and the remaining region consisting of arelatively hard material. This refinement favors the securing of thepipe attachment 48 via a clamping ring corresponding to the clampingring 8 by the tooth edge 12 being able to be readily pressed into thesofter material. Furthermore, the soft component, in exactly the samemanner as in conventional plastic pipelines, permits a later release ofthe insert part by radial deformability of the pipe/pipe attachment.

In the embodiment according to FIGS. 8 to 10, the connecting section 46is designed as a screw thread attachment 50, in particular in the formof an externally threaded connector. In this case, a screwing axis ofthe screw thread attachment 50 corresponds to the profile of the plug-inaxis 10. To screw the screw thread attachment 50 into a correspondingthreaded hole, the housing part 2 has an actuating attachment 52 inparticular in the form of an external hexagon. In order to seal off thescrewed-in housing part from the particular assembly part, a sealingring 54 is provided. As illustrated, this can be an axial sealing ringwhich is arranged in a corresponding receiving groove 56 on that endside of the actuating attachment 52 which points in the direction of thescrew thread attachment 50.

In the embodiments according to FIGS. 11 to 18, the housing part 2 isdesigned in each case as a press-in cartridge which can be inserted(plugged-in/pressed-in) with a plug-in section 58 into a connectingopening of an assembly part (not illustrated). The connecting openingcan be a simple, smooth-walled hole. It is advantageous in thisconnection if the connecting opening has a diameter which corresponds tothe core hole diameter of a threaded hole which is provided for screwingin the screw thread connector 50 according to FIGS. 8 to 10. Such is theadvantage that a manufacture of an assembly part can equip theparticular assembly part in each case with the same core hole diameter,use then being made either of the embodiment according to FIGS. 8 to 10or of one of the embodiments according to FIGS. 11 to 18. For the screwthread embodiment according to FIGS. 8 to 10, only the appropriate corehole with a matching thread needs also to be provided.

In the embodiments according to FIGS. 11 to 18, in order to provide aseal within the connecting opening, a sealing ring 60 is provided in theregion of the plug-in section 58, this sealing ring 60 being arranged ina receiving groove 62. In order to secure the housing part 2 within theconnecting opening, at least one radially protruding tooth element 64 isprovided on the outer circumference of the plug-in section 58 for theform-fitting or frictional engagement in the connecting opening. It isparticularly advantageous in this case if the plug-in section 58 has atleast one tooth element 64 which acts in the manner of a thread suchthat the housing part 2, on the one hand, can be pressed in with theplug-in section 58 axially into the connecting opening and, on the otherhand, can be removed from the connecting opening by unscrewing it. Forthis purpose, the housing part 2 preferably has, following the plug-insection 58, an actuating section 66, in particular in the form of anexternal hexagon element.

It should be expressly pointed out in this regard that these specialrefinements according to FIGS. 11 to 18 are in principle suitable forany desired housing part which can be inserted as a press-in cartridgeinto any desired connecting opening. In this respect, these features canalso be used independently of the subject matter of claim 1.

In the case of the embodiments according to FIGS. 11 to 14, the housingpart or the base part 28 consists of plastic, with, in the case of FIGS.11 and 12, a serrated ring of metal being embedded into the plasticmaterial and protruding outward together with the tooth elements 64. Inthis case, the tooth elements 64 are uniformly distributed on a circle.In the case of the embodiment according to FIGS. 13 and 14, astrip-shaped metal band in the form of a spiral-line-shaped thread isembedded into the plastic material.

In the embodiments according to FIGS. 15 to 18, the base part 28consists of metal, in particular brass, the tooth element or toothelements 64 of the plug-in section 58 being molded on as a single piece.In the embodiment according to FIGS. 15 and 16, the tooth element 64 isan annular tooth edge. According to FIGS. 17 and 18, aspiral-line-shaped threaded edge is provided as the tooth element 64.

FIGS. 19 to 27 illustrate further preferred refinement features of theinset part 32. In this preferred embodiment, the insert part 32 first ofall has an outer circumferential sealing bead 70 for sealing it offcircumferentially with respect to the base part 28. In the preferredembodiment illustrated, this circumferential sealing bead 70 consists ofa relatively soft, elastic material, and for this purpose, is molded onin particular as a single piece and with a cohesive material jointtogether with the dirt seal 34 and with the material filling thelongitudinal slots 38 (see in this respect in particular FIG. 23). Thecircumferential sealing bead 70 therefore preferably also consists of aTPE (thermoplastic elastomer). As an alternative to this, thecircumferential sealing bead 70 could, in principle, also be formed froma relatively hard material, for example the fiber-reinforced material ofthe insert part 32. However, the preferred embodiment of soft elasticmaterial leads to particular advantages, specifically to a “softsealing” and to low installation/removal forces when inserting orremoving the insert part 32, since a press fit can be omitted.

Furthermore, the insert part 32 has positioning means 72 on its outercircumference for the automatic aligning (in particular for theself-centering and self-alignment in the direction of rotation about theplug-in axis 10) on insertion into the base part 28. In the exemplaryembodiment illustrated in FIGS. 19 to 27, these positioning means 72 areformed by means of two diametrically opposite, radially projectinglongitudinal ribs 74 which run axially in the insertion direction andcan be introduced into corresponding longitudinal grooves of the basepart 28 (not illustrated) in order thereby to align the insert part 32in the correct position, so that the latching attachments 42 of thespring arms 40 can then latch correctly into the latching openings 44 ofthe base part 28.

In a further advantageous refinement, provision is made, in theembodiment according to FIGS. 19 to 27, for retaining edges to be formedwithin the insert part 32 following the inner cone 16 as an axial endstop against a movement of the clamping ring 8 that is directed in thepulling-out direction of the pipeline 6, to be precise, for firstretaining edges 76 to be formed in the region of the spring arms 40 andfor second retaining edges 78 to be formed in the regions situatedbetween the spring arms 40 or in each case between the slots 38. Thefirst retaining edges 76 are formed by radially inwardly projectingattachments 80 of the spring arms 40 (see in particular FIG. 21). Thesecond retaining edges 78 are formed, according to FIG. 26, by radiallyinwardly projecting regions 82. The retaining edges 76, 78 permit highpull-off forces, which ensures great reliability against unintentionalrelease of the pipeline 6. In a preferred refinement according to FIG.27, provision may additionally be made to offset the first retainingedges 76 with respect to the second retaining edges 78 by an axialoffset X in the direction of the inner cone 16 in such a manner that theclamping ring, when subjected to a force F_(z) acting in the pulling-outdirection of the pipeline 6, first of all only comes to bear against thefirst retaining edges 76, as a result of which the spring arms aresubjected to a radially outwardly acting retaining-force componentF_(H). However, the axial offset X here is dimensioned to be small suchthat, after a deformation in the elastic region, the clamping ringadditionally comes to bear against the second retaining edges 78, whichimproves the security against release. When the clamping ring 8 bearsagainst the first retaining edges 76, there is therefore a breaking downof force, the radial component F_(H) ensuring that the retaining forceof the elastic spring arms 40 is increased. As a result, very highpull-off forces are achieved.

The invention is not restricted to the exemplary embodiments illustratedand described, but rather also includes all embodiments of equal effectwithin the context of the invention.

While the above description constitutes the preferred embodiment of thepresent invention, it will be appreciated that the invention issusceptible to modification, variation and change without departing fromthe proper scope and fair meaning of the accompanying claims.

1. A connecting device for the plug-in connection of at least onepipeline, comprising a housing part having at least one receivingopening for the insertion of the pipeline, and a clamping ring, which isarranged in the receiving opening and, in order to lock the pipeline inplace, interacts with an inner cone of the housing part, the housingpart being made in two parts from a base part and an insert part, whichis connected to the base part via a snap-action form-fitting connectionand has the inner cone, and the insert part having a dirt seal forresting on the circumference of the inserted pipeline, the insert partformed of a first, relatively hard and dimensionally stable plasticmaterial and the dirt seal, consisting of a second, relatively soft andelastic plastic material, molded directly onto it the first material asa single piece with a cohesive material joint therebetween.
 2. Theconnecting device as claimed in claim 1 wherein the insert part is ofsleeve-shaped design and is insertable into a widened portion of thereceiving opening of the base part in a manner providing acircumferential seal against the penetration of dirt and similar foreignbodies, the insert part, in the inserted state, lying completely withinthe base part and ending flush on the receiving opening.
 3. Theconnecting device as claimed in claim claim 2 wherein the sleeve-shapedinsert part has, for the purpose of being able to release the pipeline,at least two radially elastic spring arms which are formed bylongitudinal slots and engage releasably by means of radially outwardlyprotruding latching attachments in a form-fitting manner incorresponding latching openings of the base part.
 4. The connectingdevice as claimed in claim 3 wherein the longitudinal slots are filledwith the material of the dirt seal.
 5. The connecting device as claimedin claim 1 wherein the snap-action form-fitting connection has closedlatching elements running in the circumferential direction.
 6. Theconnecting device as claimed in claim 1 wherein a supporting sleevewhich is coaxial with the plug-in axis is arranged within the base partfor the frictional engagement in the inserted pipeline.
 7. Theconnecting device as claimed in claim 1 wherein the housing can beconnected to a further assembly part via at least one connectingsection.
 8. The connecting device as claimed in claim 7, characterizedin that the connecting section is designed as a pipe attachment forinsertion into the receiving opening.
 9. The connecting device asclaimed in claim 8 wherein the base part is designed as a two-componentmolded part of plastic, the region of the pipe attachment consisting ofa relatively soft material and the remaining region consisting of arelatively hard material.
 10. The connecting device as claimed in claim7 wherein the connecting section is designed as a screw threadattachment, in particular as an externally threaded connector.
 11. Theconnecting device in particular as claimed in claim 1 wherein thehousing part can be inserted with a plug-in section as a press-incartridge into a connecting opening of an assembly part.
 12. Theconnecting device as claimed in claim 11 wherein the housing part has,on the circumference of the plug-in section, at least one tooth elementfor the engagement in the connecting opening.
 13. The connecting deviceas claimed in claim 11 wherein the plug-in section has, on itscircumference, at least one tooth element which acts in the manner of athread such that the housing part can be plugged in with the plug-insection axially into the connecting opening and can further be removedfrom the connecting opening by unscrewing it.
 14. The connecting deviceas claimed in claim 12 wherein the housing part or the base partconsists of metal, in particular brass, the tooth element or toothelements of the plug-in section being molded on as a single piece. 15.The connecting device as claimed in claim 12 wherein the housing part orbase part consists of plastic, the tooth element or tooth elementsconsisting of metal and being embedded in some regions in the plastic.16. The connecting device as claimed in claim 2 wherein the insert part,for the circumferential sealing toward the base part can be insertedinto the base part with a press fit and/or has an outer circumferentialsealing bead.
 17. The connecting device as claimed in claim 16 whereinthe circumferential sealing bead of the insert part consists of anelastic material and is molded on as a single piece with a cohesivematerial joint together with the dirt seal and preferably with thematerial filling the longitudinal slots.
 18. The connecting device asclaimed in claim 1 wherein the insert part has positioning means on itsouter circumference for the automatic aligning on insertion into thebase part, the positioning means being formed, in particular, by meansof two diametrically opposite, radially projecting longitudinal ribswhich run axially in the insertion direction and engage in correspondinglongitudinal grooves of the base part.
 19. The connecting device asclaimed in claim 1 wherein retaining edges are formed within the insertpart following the inner cone as an axial end stop for the clamping ringas an axial end stop for the clamping ring.
 20. The connecting device asclaimed in claim 19 wherein first retaining edges are formed in theregion of the spring arms and second retaining edges are formed in theregions situated between the spring arms, the first retaining edgesbeing offset with respect to the second retaining edges by an axialoffset in the direction of the inner cone whereby the clamping ring,when subjected to a force (F_(z)) acting in the pulling-out direction ofthe pipeline, first of all only comes to bear against the firstretaining edges and, as a result, the spring arms are subjected to aradially outwardly acting retaining-force component (F_(H)).